Carpal instability non-dissociative

The non-dissociative clunking wrist: a personal view

Clunking of the wrist is often the result of a combined radiocarpal and midcarpal ligament insufficiency, coupled with inadequate neuromuscular coordination. When symptomatic, these wrists may benefit from splinting, isometric exercising of specific muscles and advice on activity modification. Failing this, different surgical strategies have been proposed, depending on the location of dysfunction. When the clunking derives from an isolated injury of one joint, reconstruction of its inadequate ligaments may be an effective solution. However, soft tissue procedures tend to fail when clunking results from multilevel instability. In these cases, partial carpal arthrodesis is an alternative. Although effective in eliminating the clunking, midcarpal fusion is associated with alteration of the so-called "dart-throwing" motion, the most common rotation in daily activities, and hence is not recommended. Radiolunate fusion, by contrast, appears to be a less morbid alternative, with the benefit of eliminating the painful clunking while preserving a good range of dart-throwing motion.

Four-corner arthrodesis: influence of the position of the lunate on postoperative wrist motion: a cadaveric study

PURPOSE

Evaluate the influence of the position of the lunate on postoperative wrist motion in four-corner arthrodesis.

METHODS

Six upper cadaveric limbs were evaluated, comparing the total arc of motion in each wrist after simulating four-corner arthrodesis. The lunate was fixed in 3 different positions: neutral (0 degrees ), extended (30 degrees ), and flexed (20 degrees ). Statistical analyses (ANOVA and Bonferroni tests) were carried out to establish the significance of differences in articular motion in these 3 positions.

RESULTS

Significant statistical differences were observed in full wrist extension. No significant differences, however, were found in flexion-extension total arc of motion, radial deviation, or ulnar deviation.

CONCLUSIONS

According to our results in this cadaveric model, the position of the lunate affects postoperative wrist flexion and extension after four-corner arthrodesis. The flexed lunate position increases postoperative wrist extension and restrains wrist flexion. Inversely, the extended lunate position improves articular flexion and limits extension. Total arc of motion of the fused wrist does not vary in the 3 lunate positions.

Delayed post-traumatic midcarpal dislocation

We report a case of delayed post-traumatic volar midcarpal dislocation in a 39 year-old woman. The dislocation was a gradual process starting from the time of injury. Initial X-rays showed a normal midcarpal joint. By 6 weeks, lunocapitate subluxation was apparent radiologically and by the 18 week X-ray, midcarpal dislocation had occurred. This type of wrist injury has not been previously reported. Because of advanced degenerative changes in the lunocapitate joint, a partial wrist fusion was performed with a successful outcome.

Arthroscopic thermal capsulorrhaphy for palmar midcarpal instability

Midcarpal instability is an uncommon problem in which deficient static and dynamic wrist stabilisers cause sudden, uncontrolled movement of the proximal carpal row. We studied 15 wrists prospectively in 13 patients who underwent arthroscopic thermal capsulorrhaphy for palmar midcarpal instability. Capsulorrhaphy was performed using standard wrist arthroscopic techniques and a small diameter monopolar radiofrequency probe. One hundred percent follow-up was achieved at a mean of 42 (range 14 - 67) months. With regards to instability, all wrists showed improvement or resolution of instability. Functional improvement was confirmed by an improvement in the mean DASH score from 38 pre-operatively to 17 at final follow-up. Our early results show that thermal capsulorrhaphy is effective in reducing the instability symptoms of palmar midcarpal instability.

Injuries to the Carpal Bones Revisited

Falls on the outstretched hand, with resultant pain in the carpal region, account for a significant number of referrals to emergency rooms worldwide. Not only do they represent a significant proportion of the radiological workload arising from emergency rooms, interpretation of the images acquired is often difficult due to the complex anatomy of this region, compounded by an inability to obtain adequate views due to patient discomfort. Often, despite apparently normal radiological examinations, patient discomfort persists, prompting a need for further imaging. It is vital that the radiologist be entirely familiar with the bony and ligamentous anatomy of this body region, as well as possess an understanding of the frequent mechanisms of injury. Using a variety of imaging techniques, we illustrate a spectrum of carpal injuries, common and otherwise, explaining the mechanism and typical appearances of each.

MR Imaging of Ligaments and Triangular Fibrocartilage Complex of the Wrist

Imaging of the wrist with MR imaging can be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly understood pathologic lesions. A recent study by Hobby and coworkers of 98 patients revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. This article summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the wrist ligaments and triangular fibrocartilage complex (TFCC) of the wrist in this difficult topic in joint MR imaging.

Carpal instability

This review addresses the pathoanatomical basics as well as the clinical and radiological presentation of instability patterns of the wrist. Carpal instability mostly follows an injury; however, other diseases, like CPPD arthropathy, can be associated. Instability occurs either if the carpus is unable to sustain physiologic loads ("dyskinetics") or suffers from abnormal motion of its bones during movement ("dyskinematics"). In the classification of carpal instability, dissociative subcategories (located within proximal carpal row) are differentiated from non-dissociative subcategories (present between the carpal rows) and combined patterns. It is essential to note that the unstable wrist initially does not cause relevant signs in standard radiograms, therefore being "occult" for the radiologic assessment. This paper emphasizes the high utility of kinematographic studies, contrast-enhanced magnetic resonance imaging (MRI) and MR arthrography for detecting these predynamic and dynamic instability stages. Later in the natural history of carpal instability, static malalignment of the wrist and osteoarthritis will develop, both being associated with significant morbidity and disability. To prevent individual and socio-economic implications, the hand surgeon or orthopedist, as well as the radiologist, is challenged for early and precise diagnosis.

Understanding midcarpal instability

This article outlines the historical development of midcarpal instability observations and terminology and places them in the broader context of currently accepted theories of wrist pathomechanics. Such an understanding may help resolve the following questions: Are there 1 or more entities under the current designation of midcarpal instability? What are the underlying pathogenesis and pathomechanics of the disorder(s)? What are the recommended treatment options? What further research needs to be done to better answer these questions?

Arthroscopic dorsal radiocarpal ligament repair

PURPOSE

The goal of this study was to determine if arthroscopic repair of a dorsal radiocarpal ligament (DRCL) tear is effective in ameliorating wrist pain.

TYPE OF STUDY

Retrospective study.

METHODS

A chart review was performed of 53 patients (56 wrists) who underwent wrist arthroscopy with use of a volar radial portal. There were 21 patients with DRCL tears. Mean follow-up was 16 months. Thirteen patients underwent arthroscopic DRCL repair and/or thermal shrinkage (5 repairs, 6 repair plus shrinkage, and 2 shrinkage). Lunotriquetral tears were treated with debridement and pinning. Triangular fibrocartilage (TFC) tears were debrided or repaired. Scapholunate ligament tears/instability were treated with capsulodesis.

RESULTS

The 4 patients who underwent repair of an isolated DRCL tear had excellent results with no or mild pain. All returned to their previous occupation. Dorsal capsulodesis was performed in 7 patients with 4 fair/poor results. Nine DRCL repairs/shrinkage were in association with other procedures for ulnar-sided pathology with 6 fair/poor results.

CONCLUSIONS

Tears of the DRCL are more common than previously suspected. They are best seen through a volar radial portal and are amenable to arthroscopic repair. DRCL tears appear to be part of a spectrum of radial and ulnar-sided carpal instability as evidenced by the frequent association with scapholunate ligament tears/instability or ulnar-sided pathology. Isolated DRCL tears can be solely responsible for wrist pain. Good results are obtained with arthroscopic repair of isolated DRCL tears. The presence of a DRCL tear when seen in combination with a scapholunate, lunotriquetral, or TFC tear connotes a greater degree and/or duration of carpal instability, and portends a poorer prognosis following treatment. Recognition of this condition and further research into treatment methods is needed.

LEVEL OF EVIDENCE

Level IV.

Wrist MR Arthrography: How, Why, When

MR imaging of the wrist frequently represents a diagnostic challenge for radiologists because of the complex anatomy of this joint, small size of its components, and little known pathologic conditions. MR arthrography combines the advantages of conventional MR imaging and arthrography by improving the visualization of small intra-articular abnormalities. This article reviews the current role of MR arthrography in the evaluation of wrist joint disorders considering the relevant aspects of anatomy, techniques, and applications.

MR imaging of ligaments and triangular fibrocartilage complex of the wrist

Imaging of the wrist with MR imaging can be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly understood pathologic lesions. A recent study by Hobby and coworkers of 98 patients revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. This article summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the wrist ligaments and triangular fibrocartilage complex (TFCC) of the wrist in this difficult topic in joint MR imaging.

[Lesions of the wrist disc. Pathology, diagnosis and treatment]

Lesions of the TFCC are currently a diagnostic and therapeutic challenge. Disc-injuries are often not identified and, therefore, acute ruptures are unfortunately not always immediately repaired. Moreover, therapeutic measures are still sparse and informative trial results are lacking. An anatomical, pathological, diagnostic and therapeutic comparison with the meniscus of the knee is possible.

Palmar midcarpal instability: the results of treatment with 4-corner arthrodesis

PURPOSE

Palmar midcarpal instability (PMCI) is one type of nondissociative carpal instability. The optimal treatment for PMCI is uncertain. The purpose of this investigation was to evaluate the results of capitate-lunate-triquetrum-hamate (4-corner) arthrodesis for PMCI.

METHODS

Over a 10-year period 8 patients were treated with 4-corner arthrodesis for PMCI. The instability was diagnosed clinically and confirmed with cineradiography. The symptomatic instability began in all patients after a notable trauma; 6 of the patients were injured at work and 2 were injured in a motor vehicle accident. Patients were evaluated at an average of 34 months after surgery.

RESULTS

Seven of the 8 patients were satisfied with the surgery and 6 of 8 patients had no pain or mild pain. Both patients injured in motor vehicle accidents returned to all preinjury activities. Four of the 6 workers' compensation patients returned to work, 3 at full duty and 1 in a restricted position. Two patients, both with workers' compensation, did not return to their pre-injury jobs. One had occasional moderate pain and the other had chronic pain. The average wrist flexion/extension arc of motion decreased with surgery from 135 degrees to 75 degrees. The average grip strength increased significantly with surgery from 20 kg to 32 kg; however, grip strength remained significantly lower than the opposite side strength of 54 kg.

CONCLUSIONS

Four-corner arthrodesis is a reasonable option for PMCI. Compared with previous reports of soft tissue reconstruction 4-corner arthrodesis may provide a more reliable solution for this difficult problem.

Relationship between joint laxity and radio-ulno-carpal joint morphology

The relationships between wrist laxity, ulnar variance, sigmoid notch inclination, and lunotriquetral motion were analysed in 60 normal volunteers. A strong correlation between ulnar length and sigmoid notch inclination was found for the entire group. Joint laxity was found to correlate with ulnar variance and lunotriquetral mobility in women, but not in men. The greater the laxity, the shorter the ulna and the greater the lunotriquetral motion during radial to ulnar deviation. These results support the concept that laxity increases the vulnerability of the wrist to injury.

Extrinsic carpal ligaments: normal MR arthrographic appearance in cadavers

PURPOSE

To describe the normal magnetic resonance (MR) arthrographic anatomy of the major carpal ligaments (excluding scapholunate and lunotriquetral ligaments) and their osseous attachments by using standard imaging planes.

MATERIALS AND METHODS

MR images of 22 wrists derived from fresh human cadaveric hands were obtained after tricompartmental arthrography. The MR arthrographic appearance of the carpal ligaments and their bone attachments were analyzed and correlated to those seen on anatomic sections. Two readers determined in consensus which was the best plane to observe the course and attachment sites for each ligament. They further analyzed the size and sites of attachment of these ligaments in two orthogonal planes chosen for optimal viewing.

RESULTS

Each ligament was well seen as a hypointense linear structure with MR arthrography. The radioscaphocapitate, radiolunotriquetral, radioscapholunate, dorsal radiotriquetral, palmar scaphotriquetral, and dorsal scaphotriquetral ligaments were best evaluated in the transverse plane. The palmar and dorsal ulnotriquetral and ulnolunate ligaments were best visualized in the sagittal plane. The radial collateral ligament was best analyzed in the coronal plane. The attachment sites of all ligaments were best analyzed either in the transverse or sagittal planes.

CONCLUSION

MR arthrography allows visualization of the carpal ligaments. Detailed knowledge of the normal appearance of these ligaments can serve as a baseline for future studies in which MR arthrography is used to characterize wrist instability.

Acute wrist injuries in the athlete

The athlete represents a special population in which injuries can occur either from a single acute traumatic event or as part of a continuum of overuse that leads to osseous or soft tissue failure. The spectrum of overuse with superimposed acute trauma makes the evaluation of the upper extremity in the competitive athlete more challenging. The expectation of this population for quick, full, painless recovery, coupled with the desire to return to the sport that caused the injury, makes the treatment difficult as well. This article will discuss athletic injuries of the forearm and wrist with an emphasis on evaluation, treatment, and criteria for return to play.

Ligamentous injuries of the wrist in the athlete

Wrist instability most commonly results from ligamentous disruption between bones of the proximal carpal row. Scapholunate and lunotriquetral dissociation are forms of this instability pattern. Carpal instability can also occur due to loss of the normal ligamentous restraints between the carpal rows. Ulnar midcarpal instability is an example of this pattern. The treatment of wrist instability depends on the specific type and degree of carpal disruption and the presence or absence of degenerative changes. Options include soft-tissue reconstruction, partial wrist fusion, limited carpal bone excision, or a combination of methods.

The unstable capitolunate and radiolunate joints as a source of wrist pain in young women

A retrospective study of 12 young women (14 cases) complaining of chronic wrist pain, obscure numbness and reduction of grip strength is presented. The average duration of the complaints was 7.3 years. All wrists were in VISI alignment, with normal motion series and normal intrinsic interosseous ligaments demonstrated arthrographically. The dorsal-displacement stress test showed subluxation of the capitolunate (in nine cases) or both the capitolunate and the radiolunate joints accompanied by a marked feeling of apprehension. Surgical management consisted of ligamentous reefing of the whole palmar aspect of the midcarpal joint and the radiolunate joint when needed. Additionally, a neurectomy of the terminal branch of the anterior interosseous nerve was done in four cases. The result was excellent in eight cases, good in five cases and fair in 1 case. Young women with "delicate" wrists and obscure wrist pain may have isolated instabilities of the capitolunate and radiolunate joints. In cases that do not respond to conservative measures ligamentous reefing should be considered.

Analysis of carpal instability: II. Clinical applications

An analytic scheme for carpal instability patterns has been described to help standardize reporting of these conditions. Six categories to be recognized in each case are chronicity, constancy, etiology, location, direction, and pattern. Examples are presented to illustrate the use of this scheme.